1. Technical Field
Example embodiments relate to an image sensor, and more particularly to an analog-to-digital converter that reduces noise and an image sensor including the analog-to-digital converter.
2. Description of the Related Art
Generally, an analog-to-digital converter included in an image sensor is implemented with metal oxide semiconductor (MOS) transistors.
If defects exist in an oxide layer of a MOS transistor, electrons or holes flowing through a channel of the MOS transistor may be trapped in the defects, or electrons or holes trapped in the defects may be de-trapped. Therefore, a magnitude of a current flowing through a channel of a MOS transistor may vary based on an amount of electrons or holes trapped in the defects or de-trapped from the defects, which may cause random telegraph signal (RTS) noise in the MOS transistor.
When RTS noise occurs in an analog-to-digital converter included in an image sensor, performance of the image sensor may be degraded.